The present invention relates to a binocular.
A binocular has left and right telescope systems, each telescope system including an objective system, an erecting system and an eyepiece system.
There is a known binocular having an adjusting mechanism, wherein the eyepiece system of each telescope system is moved toward and away from a front-most lens of the objective system for a focus adjustment or the like.
However, in such a binocular, since it is necessary to provide enough space between the erecting system and the eyepiece system to allow for the movement of the eyepiece system, the size of the binocular can not be reduced.